A mother is Rh-negative, and her fetus is Rh-positive. She delivered her first Rh-positive baby without receiving Rho(D) immune globulin. Which complication may occur in a future pregnancy if sensitization has occurred?

A. Hypoglycemia in newborns is generally caused by maternal diabetes, preterm birth, intrauterine growth restriction, or perinatal stress. It occurs because the newborn produces excess insulin or has limited glycogen stores. Rh sensitization does not affect glucose metabolism, so neonatal hypoglycemia is unrelated to maternal Rh status. B. If an Rh-negative mother becomes sensitized after delivering an Rh-positive infant without receiving Rho(D) immune globulin, she can form anti-Rh antibodies. In a future pregnancy with an Rh-positive fetus, these antibodies can cross the placenta and destroy fetal red blood cells, causing hemolytic disease of the newborn (HDN). Severe HDN may lead to fetal anemia, hydrops fetalis, or miscarriage/stillbirth if left untreated. C. Macrosomia, defined as birth weight >4,000–4,500 g, is typically associated with maternal diabetes, maternal obesity, or genetic predisposition. Rh incompatibility does not influence fetal growth or increase the risk of macrosomia, so it is not a concern in sensitized mothers. D. Placenta previa occurs when the placenta partially or completely covers the cervical os, which can cause bleeding during pregnancy. Its risk factors include previous cesarean delivery, uterine surgery, multiple gestations, or advanced maternal age, but Rh sensitization has no effect on placental location, so it is unrelated.